Smith is best known for his novels featuring Russian investigator Arkady Renko whom Smith introduced in Gorky Park (1981). The novel, which was called the "first thriller of the '80s" by Time,[5] became a bestseller and won a Gold Dagger Award from the British Crime Writers' Association.[6] Renko has since appeared in seven other novels by Smith. Gorky Park debuted at number one on the "New York Times" bestseller list on April 26, 1981 and hung onto the top spot for another week. It stayed in the number two position for over three months, beaten only by James Clavell's Noble House. It stayed in the top 15 through November of that year. Polar Star also claimed the number one spot for two weeks on August 6, 1989. It subsequently held the number two spot for over two months.

During the 1990s, Smith twice won the Dashiell Hammett Award from the North American Branch of the International Association of Crime Writers. The first time was for Rose in 1996; the second time was for Havana Bay in 1999. And on September 5, 2010, he and Arkady Renko returned to the top of the New York Times bestseller list when Three Stations debuted at number seven on the fiction bestsellers list.

In the 1970s, Smith wrote two Slocum adult action Western novels under the pen nameJake Logan.[7] Smith has also written a number of other paperback originals, including a series about a character named "The Inquisitor", a James Bond-type agent employed by the Vatican. Smith also wrote two novels in the Nick Carter series.

He originally wrote under the name "Martin Smith", only to discover there were other writers with the same name. His agent asked Smith to add a third name and Smith chose Cruz, his paternal grandmother's surname.[7]